(3/10)+(-4/11)+(6/5)+(-12/7) (-3.5)+(-3/4)+(-4/3)+(+2/7)+0.75+(-3/7)用简便方法计算 实在算不出来了已知/2a-1/+/5b-4/=0a的相反数与b的倒数的和a的绝对值与b的绝对值的和
问题描述：
(3/10)+(-4/11)+(6/5)+(-12/7) (-3.5)+(-3/4)+(-4/3)+(+2/7)+0.75+(-3/7)用简便方法计算 实在算不出来了
已知/2a-1/+/5b-4/=0
a的相反数与b的倒数的和
a的绝对值与b的绝对值的和
答
(3/10)+(-4/11)+(6/5)+(-12/7)
=3/10-4/11+6/5-12/7
=(3/10+6/5)-(4/11+12/7)
=3/2-160/77
=-89/154
2.(-3.5)+(-3/4)+(-4/3)+(+2/7)+0.75+(-3/7)
=-3.5+(-3/4+0.75)+(2/7-3/7)-4/3
=-3.5+0-1/7-4/3
=-(7/2+1/7+4/3)
=-(147+6+56)/42
=-209/42